Commercially available photonics integrated circuits are fabricated on wafers, such as bulk silicon or silicon-on-insulator wafers. Commercially available prefabricated photonics integrated circuit chips can include waveguides for transmission of optical signals between different areas of a prefabricated photonics integrated circuit chip. Commercially available waveguides are of rectangular or ridge geometry and are fabricated in silicon (single or polycrystalline) or silicon nitride. Commercially available photonics integrated circuit chips are available on systems having a photonics integrated circuit chip disposed on a printed circuit board.